Breeding and Genetics: Dairy Cattle Breeding II and Rabbit Breeding

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Heritability of maturity rate was 0.09 when maturity rate was defined as the difference ..... T31 Genetic correlations of dry matter intake with fat corrected milk yield, body .... T34 Beta-casein enhancer (BCE) and evolutionarily conserved region 3 ..... exposure and soluble in some non-polar solvents, such as pentane and.
somatic cell count (SCC) or California Mastitis Test (CMT). The tests were used to detect intramammary infection (IMI) for different DIM (2 to 8), parity statuses (heifer or cow), and a defined SCC threshold. Producer decisions for each cow included (1) test or no test, (2) if test is pursued, what type of test (CMT or SCC), and (3) a final decision: cull, segregate, administer antibiotics, or take no action. Each intermediate or final node of the model was associated with an economic outcome that the decision tree used to find the economically optimal pathway. The cost of subclinical mastitis was assessed as the aggregation of five factors: (1) milk loss, (2) milk premium loss, (3) premature culling, (4) clinical flare-ups, and (5) transmission to herd mates. These costs were a function of the lactation curve, milk price, defined SCC threshold, livestock prices, and a defined prevalence of contagious mastitis pathogens. Preliminary results indicate, in general, the selection of CMT and no action for negative cows. Seems that the administration of antibiotics could be a feasible option for positive cows, especially when a cow is in first parity (increased rate of cure), milk from a treated cow is used for heifer feeding, and the prevalence of contagious pathogens is high. The cost of mastitis under an optimal policy would vary between $142 to $225 per cow per 305-d lactation, and depend strongly on mastitis prevalence, SCC threshold, milk price, milk production level of cow, and parity. Key Words: decision tree, mastitis cost, mastitis economic impact

T14 Effects of CpG ODN adjuvant on the immune responses elicited by a quadrovalent mastitis vaccine in dairy cows. S.-C. Lee1 and J.-W. Lee*2, 1Graduate Institute of Animal Vaccine Technology, National Pingtung University of Science and Technology, Neipu, Pingtung, Taiwan, 2Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Neipu, Pingtung, Taiwan. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) remain to be common pathogens inducing bovine mastitis worldwide. Prevention of mastitis by using vaccines has not been very successful. Accumulated lines of evidence indicated that the efficacy of a vaccine can be enhanced by using bacterial DNA, or synthetic CpG oligodeoxynucleotides (ODNs), as the adjuvant. In the present study, a quadrovalent mastitis vaccine, containing formalin inactivated three strains of S. aurues (T5, T8, and smith compact) and E. coli J5, was formulated with or without a sequence of CpG ODNs that has been shown to be immunostimulatory to bovine cells. Eighteen healthy dairy cows were randomly assigned to three groups and received (1) the control (Freund’s incomplete adjuvant, FIA, alone, n=6), (2) Vaccine + FIA (n=6), and (3) Vaccine + FIA + CpG (n=6). Serum antibodies specific to the four strains of bacteria and the expression of cytokines, including interferon-gamma (IFN-γ) and IL-4, in peripheral blood mononuclear cells (PBMC) in response to killed bacteria were analyzed by real-time PCR. In comparison with the control, titers of serum antibody specific to the three S. aureus strains were significantly (p < 0.05) increased.

Addition of CpG ODNs into the vaccine did not enhance the production of antibodies. However, PBMC from cows immunized with CpG ODNs as the adjuvant had a significantly increased expression of IFN-γ (11 v.s. 4 folds) and decreased expression of IL-4 (2 v.s 10 folds) at the transcriptional level. Results indicated that inclusion of CpG ODNs as the adjuvant in an inactivated mastitis vaccine can enhance Th1 type immune responses, which might be beneficial to the elimination of bacteria by phagocytes. Key Words: vaccine, CpG, mastitis

T15 Intramammary glucocorticoid treatment during LPS-induced mastitis. O. Wellnitz, M. Saudenowa, and R. M. Bruckmaier*, University of Bern, Vetsuisse Faculty, Veterinary Physiology, Bern, Switzerland. Therapeutically used glucocorticoids have dose-dependent effects on the immune system. Glucocorticoids such as prednisolone (Pred) are traditionally added to antibiotic intramammary injectors aiming to support the cure of the inflamed mammary gland. The goal of the study was to evaluate the effects of Pred at the dosage commonly used in intramammary injectors on the immune system of the mammary gland and to evaluate the influence of Pred on the mammary immune response to E. coli lipopolysaccharide (LPS) stimulation. Five healthy lactating dairy cows with quarter somatic cell counts (SCC) below 120 × 103 cells/mL were intramammarily infused with either Pred (10 mg), LPS (100 μg), Pred+LPS, or saline solution (9 g/l) in one out of four quarters, respectively. Udders were completely emptied by machine milking every 12 h. SCC of each quarter, tumor necrosis factor alpha (TNF) in milk, and lactate dehydrogenase (LDH) in milk were measured at 0, 3, 6, 9, 12, 24, and 36 h. mRNA expression of TNF, interleukin (IL)-1beta, IL-8, IL-10, and lactoferrin (LF) were measured in milk cells at 0, 12, 24, and 36 h using qRT-PCR. Differences between treatments were considered significant if P